Thermolysis of Coal Tar Pitch alpha2-Fraction: Characteristics of the Coke Structure
S. A. SOZINOV, A. N. POPOVA, S. YU. LYRSHCHIKOV, Z. R. ISMAGILOV
Federal Research Center of Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Kemerovo, Russia
Keywords: alpha-fraction, coal-tar pitch, thermolysis, coke
Pages: 532-537
Abstract
Methods of scanning electron microscopy, NMR spectroscopy, XRD, thermal analysis and gas chromatography-mass spectrometry have been used to study the composition, structure and morphology of particles of α2-fraction powders isolated by the method of selectively soluble groups from medium-temperature coal-tar pitch. It is shown that the α2-fraction is mainly a mixture of condensed aromatic compounds containing N, O and S heteroatoms, while sulphur is mainly contained in the form of heat-resistant thiophene compounds. The study of coke particles formed during the thermolysis of the α2-fraction showed that in the temperature range from 300 to 600 oC, a dense structure with carbon content 90-93 % is formed from the substances of the α2-fraction. Further heating up to 1200 oC leads to an increase in the carbon content up to 97 %, while the coke particles form a layered structure with pronounced anisotropy, approaching the structural characteristics of La and Lc to “premium class” needle cokes.
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